Inkjet printers form a printed image by ejecting or “jetting” drops of liquid ink onto an image receiving surface, such as an intermediate transfer surface or a media substrate. Inkjet printers typically include a printhead and a printhead controller. The printhead controller, among other functions, generates and sends firing signals to the printhead. The firing signals are delivered to inkjet ejectors in the printhead to cause the inkjets to eject drops of liquid ink upon an image receiving surface to form at least a portion of a printed image.
In general, the printhead of an inkjet printer includes a plurality of ink ejectors and at least one reservoir for containing a supply of ink. Specifically, a monochromatic inkjet printhead may include a single reservoir in which a single color of ink is stored. A full color inkjet printhead may include a plurality of reservoirs, with each reservoir configured to contain a different color of ink. The ink ejectors eject very small drops of the ink onto an image receiving surface in response to receiving a firing signal from the printhead controller. Often, a group of one hundred to six hundred individual ink ejectors in a printhead are coupled to an ink reservoir. In particular, a monochromatic printhead may include a single group of ink ejectors fluidly coupled to the single reservoir, while a full color printhead may include a separate group of ink ejectors for each of the reservoirs. Thus, a full color printhead having four reservoirs may have four distinct groups of ink ejectors, each being coupled to a different ink reservoir. The ink drops ejected from the printhead may have various masses and the inkjet ejectors may eject the drops with different velocities. The mass and velocity of ink drops may affect image quality, and a single printer may have multiple print modes that operate the printheads to eject ink drops with different masses and velocities. Consequently, further developments in the operation of inkjet printheads are desirable.